Plugin System

[arves100]

Somewhere in the future, adding the support of a Plugin system would be handfull for a couple of things.

For example: An user could connect the authentication of his forum software to RetroSpy.

I currently don't have any clear idea on how to make such plugin system. Please report any ideas or design pattern to use in the following issue.

I won't currently prioritize this issue since the emulator doesn't completely support GameSpy services yet.